The present invention relates to a device for regulating the flow of blood in blood vessels.
The blood system, and in particular the venal blood system of the legs and arms are provided with valves, at predetermined positions, which ensure that blood cannot flow back along the system in the direction from which it has just been pumped, to only be displaced in the direction of the heart.
In the arms and legs, there is a deep and a surface venal system.
Due to various causes, thrombosis can occur in especially the deep venal system. Following thinning of the blood, passage of the blood through the system is often again possible, but in this case the valves do not effectively close off the system and often leak. This causes an increased venal blood pressure in the direction of the ankles, which leads to many problems, such as varicose veins and the infamous xe2x80x9copen legxe2x80x9d. This type of complaint, is wide spread among people who spend a vast majority of their working hours in a standing position, for instance surgeons.
The surface venal system of the leg is weaker than the deep system, and has the tendency to spontaneously widen, whereby the valves no longer function effectively, leading to varicose veins, which, apart from being highly unattractive, are also very painful. Major surgery is often required to deal with these blood vessel valve problems.
For example varicose veins are presently surgically operated on, by either closing off the vein, which leads to a reduced blood flow capacity and extra pressure on surrounding blood vessels in order to ensure blood supply, or by completely removing the varicose veins, which leads to the same problem.
An object of the present invention is to obviate one or more of these problems.
According to a first aspect, the present invention provides a device for regulating the flow of blood in blood vessels, comprising one or more flow stoppage elements, each comprising:
a flareable proximal end, flareable between a flared, flow stoppage configuration and a substantially flattened, flow permitting configuration, and
a middle section extending from the proximal end to terminate in a distal end.
By introducing a synthetic device which acts as a valve, the blood flow is now able to be regulated in substantially the normal manner.
The device preferably further comprises:
an opening associated with the proximal end, the middle section comprising one or more sidewalls extending from this proximal end opening to join together at the distal end, the sidewalls being displaceable, by the flow of blood through the device between the flared configuration, wherein the element encloses a temporary blood storage area, and the substantially flattened configuration wherein the one or more sidewalls lie substantially flat adjacent to each other.
When occupying the blood flow stoppage configuration, the flow stoppage element encloses a temporary blood storage area between its open proximal end and the closed distal end. In this way between heartbeats, which force the blood through the venal system, any blood flowing in the opposite direction to the blood stream opens the proximal end of the stoppage element thereby forcing the sidewalls apart to enter the temporary blood storage area, instead of passing through the device to leak back into the blood vessel in the direction from where it has just been pumped. Since opening of the blood flow stoppage element effectively closes off the blood vessel, a very effective valve is provided.
The flow stoppage element is preferably mounted on a support having such a form as to pass within a blood vessel. This provides extra stability.
The stoppage element is preferably substantially conical in shape when occupying the blood flow stoppage configuration, the closed distal end being synonymous with the tip of the cone and the proximal end opening being synonymous with the flared base of the cone. This yields a highly effective valve working.
The support is preferably adjustable between an introducing form, wherein the device is suitable for introducing into a blood vessel, and an expanded form suitable for supporting the stoppage element within a blood vessel at the desired working location thereof, and most preferably has such a form as to have substantially the same length when occupying its introducing form as when occupying its expanded form. Accordingly the device can be effectively introduced to a pre-desired location within a blood vessel, whereafter it is expandable to take up its working form. Since the support has substantially the same length when in its introducing form as in its expanded form, the stoppage elements remain effectively supported, and any damage ensuing from alteration of the length of the support within the blood system is effectively obviated.
In order to yield a very effective valve working, the support preferably comprises substantially separate frame sections for each of the one or more fluid passage stoppage elements.
According to another aspect of the present invention, there is provided a support for a fluid stoppage element as referred to above.
According to yet a further aspect of the present invention there is provided a method for regulating the flow of blood in the blood stream comprising introducing the above device into a blood vessel, so that the distal end thereof is arranged downstream from the proximal end, wherein the proximal end opening is closed by the pressure of blood flowing through the device, as blood is pumped through the system by the heart, wherein blood flowing in the opposite direction to which it is pumped between beats, flows into the proximal end of the device, which is subsequently thereby opened to force the sidewalls of the device against the blood vessel walls, thereby closing off the passage of blood in the blood vessel, wherein blood is trapped in the temporary blood storage area enclosed by the sidewalls of the device before a subsequent volume of blood being pumped through the device claps said sidewalls shut, thereby expelling blood out of the temporary storage area and further through the system.